Improvement in bolt-threading dies



L. W. STOCKWELL.

BOLT-TH-READING DIES. No. 178,484. Patentediune 6,1876.

N. PETERS PMOTO-LITHUGRAPMER, WASHINGTON D C UNITED Snares;

LEVI W. STOCKWELL, OF RAVENNA, OHIO, ASSIGNOR TO STOOKWELL,

' BRAGG & 00., or SAME PLACE.

IMPROVEMENT IN BOLT-THREADING DIES.

Specification forming part of Letters Patent No. 178,484, dated June 6,1876; application filed March 3, 1876. 7

To all whom it may concern:

Be it known that I, LEVI W. S'rooKwELL, a resident of Ravenna, Portagecounty, Ohio, have invented a new and useful Improvement inBolt-Threading Machines, which improvement is fully set forth in thefollowing specification, reference being had to the accompanyingdrawings.

The object of this invention is to thread bolts by dies held in aspindle, which may be attached to, or held by, an ordinary brace forholdinga bit, the dies being opened and closed by a sliding cam-ring,operated by turning a collar on the threaded part of the spindle.

Figure l is a view of the machine. Fig. 2 is a longitudinal section ofthe machine, showing the relative positions of the spindle and cam-rin gfor the dies to be removed or replaced.

The head of the spindle a is hollow, to permit the bolt to enter it. Theshank of the spindle is shaped to enter the socket of a brace, by whichit may be operated. The dies 0 c c c are placed in slots in thespindlehead, to which the face-plate g is fastened. The dies. are closedagainst the bolt to be threaded, and are withdrawn from it by thesliding cam-ring b, in which are slots converging from its face, for theouter ends of the dies to enter. The converging cams formed by theseslots in the cam-ring force in the dies by pressing against their outerends, which are shaped to fit the faces of the cams. There is a groove,0, in the camring b, on one side of each slot, parallcl with the cam,for a pin in the die 0 to enter, and by means of which the dies arewithdrawn from the bolt when threaded.

When the cam-ring b is moved forward on the'spindle a, the dies 0 c c care forced in toward the axis of the spindle, and when the cam-ring ismoved back, the lower side of the grooves 0 0 0 0 press against theunder side of the pins in the sides of the dies 0 c c c, and thuswithdraw the dies from the bolt.

The cam-ring b is operated by the collar h, from which projecting pinsenter the groove in the circumference of the cam-ring b. The collar histurned in a screw-thread on the spindle a, and, by means of the pinswhich project from the collar into the groove 6, a reciprocating motionis thus given to the cam-ring b, for the purpose of opening and closingthe threading-dies. On the face of the cam-ring b is an annularshoulder, 01, whose circumference and the inner sides of the outer endsof the grooves 0 0 o o are equally distant from the axis of the spindle.The slots in the camring pass through the shoulder d. To place the diesin the spindle-head, the cam-ring b is drawn back by turning the collarh on the screw-thread of the spindle at until the camring and spindleare in the relative positions shown in Fig. 2. The dies are then placedin the spindle through the slots in the shoulder d, with the die-pinsresting on the circumference of the shoulder at at the open ends of thegrooves o 0 0 0, and then the dies are in position to enter the slots inthe cam-ring b. The motion of the collar h on the screw-thread of thespindle is then reversed, sliding forward the cam-ring over the dies,and forcing them into the proper position for threading the bolt, whichis indicated by an index-scale on the circumferences of the cam ring I)and the collar It at their junction. The collar n on the spindle a,between its shank and the thread of the spindle, is provided with astop-pin, s, which projects beyond the circumference of the collar n,and forms a stop for the finger x. The finger :nis firmly attached tothe circumference of the collar h, and projects across the circumferenceof the collar n. It may be made of a thin piece of metal. The collar ais also provided with a set-screw, 'w.

When the collar h has been turned till the dies are in position forthreading the bolt, the collar n is turned until the pin .9 comes incontact with the finger 00, and then the-setscrew w is tightened to holdthe collar n from turning, and to prevent the collar h from turm ing, soas to force in the dies farther than required for threading the bolt.The finger ac and stop-pin 8 do not prevent the collar h from beingturned in the opposite direction, whichjs done by the hand of theoperator after the bolt is threaded, to open the dies and release thebolt. When another bolt is placed in position to be threaded, the collarh is turned till the finger it again comes in contact with the stoppins, which forces the dies in till they are 2. The collar n, having theset-screw w and again in the same position as before for threadthestoppin s, in combination with the finger ing the bolt. av on the collarh, substantially as and for the I claim as my inventionpurpose hereinset forth.

1. The sliding cam-ring I), having the annular shoulder 01 for the pinsor projections of LEVI W. STOOKWELL. the threading-(lies to rest on atthe outer ends Witnesses: of the grooves o 0 0 o, substantially as andGEORGE F. ROBINSON,

for the purpose herein set forth. BRADFORD HOWLAND.

